Integrated circuit optoelectronic toggle F/F

Abstract

A pulse converter includes a set-reset flip/flop, or OPTOGLE 10, having a pair of cross-coupled switching devices such as transistors Q1, Q2 or logic gates G1, G2. The circuit operates by coupling pulses of optical radiation to each of the devices for causing the devices to alternately toggle between an on-state and an off-state. Optical inputting devices such as photodiodes or photoconductors, or the gates of FET transistors themselves, are integrally formed upon a common substrate with the switching devices for minimizing stray inductive and capacitive reactances to substantially eliminate temporal jitter in an electrical output signal. A pulsed laser source and a fiber optic or optical waveguide provide non-overlapping optical pulses to each of the switching devices. In accordance with one embodiment each of the switching devices is a GaAs MESFET device having a gate terminal comprised of a substantially transparent layer of electrical conductor having an interdigitated geometry and an overlying anti-reflection (AR) coating.

Having thus described our invention, what we claim as new, and desire to secure by Letters Patent is: 
     
       1. Clock generator integrated circuit apparatus for generating a periodic electrical signal comprising: set-reset flip/flop means comprised of a first switching means and of a second switching means both of which are fabricated upon a common substrate, an output electrical terminal of the clock generator integrated circuit apparatus being coupled to an output terminal of one of the switching means; and   means for receiving pulses of optical radiation integrally formed on the common substrate with each of the switching means, the receiving means comprising a first optical receiver means and a second optical receiver means each being coupled to an input of an associated one of the switching means for causing, in response to the receipt of a pulse of optical radiation by one of the optical receiver means, the associated switching means to toggle between an off-state and an on-state for generating a change of state of an electrical signal at the output electrical terminal of the clock generator integrated circuit apparatus.   
     
     
       2. Apparatus as set forth in claim 1 wherein each of the switching means is comprised of a transistor device fabricated from a semiconductor material having a characteristic energy bandgap for absorbing the optical pulse and generating sufficient charge carriers therefrom to induce a current flow through the transistor. 
     
     
       3. Apparatus as set forth in claim 2 wherein the semiconductor material is comprised of Group III-V material. 
     
     
       4. Apparatus as set forth in claim 2 wherein the semiconductor material is comprised of silicon. 
     
     
       5. Apparatus as set forth in claim 1 wherein the receiving means couples the associated switching means to an output of a pulsed laser source. 
     
     
       6. Apparatus as set forth in claim 5 and including fiber optic means for conveying the output of the laser source to the receiving means. 
     
     
       7. Apparatus as set forth in claim 5 and including optical waveguide means for conveying the output of the laser source to the receiving means. 
     
     
       8. Apparatus as set forth in claim wherein the receiving means is coupled to an output of a laser means. 
     
     
       9. Apparatus as set forth in claim 1 wherein each of the switching means is comprised of a field effect transistor (FET) device fabricated from a semiconductor material having a characteristic energy bandgap for absorbing the optical pulse and generating sufficient charge carriers therefrom to induce a current flow though the FET device, and wherein the receiving means comprises a gate terminal region of the FET device. 
     
     
       10. Apparatus as set forth in claim 9 wherein the gate terminal has an interdigitated geometry and is disposed adjacent to an anti-reflection coating. 
     
     
       11. Apparatus as set forth in claim 1 wherein each of the switching means is comprised of a field effect transistor (FET) device, and wherein the receiving means is comprised of a photovoltaic device coupled to a gate terminal of the FET device. 
     
     
       12. Apparatus as set forth in claim 1 wherein each of the switching means is comprised of a field effect transistor (FET) device, and wherein the receiving means is comprised of a photoconductive device coupled to a gate terminal of the FET device. 
     
     
       13. Apparatus as set forth in claim 1 wherein each of the switching means is comprised of a logic element. 
     
     
       14. Apparatus as set forth in claim 13 wherein the logic element has at least two inputs and operates in accordance with a NOR function. 
     
     
       15. Apparatus as set forth in claim 1 wherein the receiving means is coupled to an output of a pulsed laser source through an intervening optical waveguide means, and wherein the optical waveguide means is also integrally formed upon the common substrate. 
     
     
       16. Pulse conversion apparatus for converting an optical pulse into an electrical pulse, comprising: first transistor means having an output terminal coupled to an associated load means, the first transistor means further having a control terminal;   second transistor means having an output terminal coupled to an associated load means, the second transistor means further having a control terminal, the first and the second transistor means being cross-coupled such that the control terminal of the first transistor means is coupled to the output terminal of the second transistor means and the control terminal of the second transistor means is coupled to the output terminal of the first transistor means, the output terminal of the first transistor means further being coupled to an output terminal of the pulse conversion apparatus, the first and the second transistor means each being fabricated upon a common substrate; and   means for inputting pulses of optical radiation to the control terminal of the first transistor means and for inputting pulses of optical radiation to the control terminal of the second transistor means for causing the first and the second transistor means, in response to the receipt of a series of pulses of optical radiation by the inputting means, to toggle, for each received optical pulse, between a conducting state and a nonconducting state and for causing an electrical output signal appearing at the pulse conversion apparatus output terminal to toggle between a first logic state and a second logic state, the inputting means being integrally formed upon the common substrate with the first transistor means and the second transistor means for minimizing stray inductive and capacitive reactances for substantially eliminating temporal jitter of the electrical output signal.   
     
     
       17. Pulse conversion apparatus for converting an optical pulse into an electrical pulse, comprising: first transistor means having an output terminal coupled to an associated load means, the first transistor means further having a control terminal;   second transistor means having an output terminal coupled to an associated load means, the second transistor means further having a control terminal, the first and the second transistor means being cross-coupled such that the control terminal of the first transistor means is coupled to the output terminal of the second transistor means and the control terminal of the second transistor means is coupled to the output terminal of the first transistor means, the output terminal of the first transistor means further being coupled to an output terminal of the pulse conversion apparatus, the first and the second transistor means each being fabricated upon a common substrate; and   means for inputting pulses of optical radiation to the control terminal of the first transistor means and for inputting pulses of optical radiation to the control terminal of the second transistor means for causing the first and the second transistor means to alternately toggle between a conducting state and a nonconducting state and for causing an electrical output signal appearing at the pulse conversion apparatus output terminal to toggle between a first logic state and a second logic state, the inputting means being integrally formed upon the common substrate with the first transistor means and the second transistor means for minimizing stray inductive and capacitive reactances for substantially eliminating temporal jitter of the electrical output signal, wherein the inputting means is comprises of a first photodiode coupled to the control terminal of the first transistor means and a second photodiode coupled to the control terminal o the second transistor means.   
     
     
       18. Pulse conversion apparatus for converting an optical pulse into an electrical pulse, comprising: first transistor means having an output terminal coupled to an associated load means, the first transistor means further having a control terminal;   second transistor means having an output terminal coupled to an associated load means, the second transistor means further having a control terminal, the first and the second transistor means being cross-coupled such that the control terminal of the first transistor means is coupled to the output terminal of the second transistor means and the control terminal of the second transistor means is coupled to the output terminal of the first transistor means, the output terminal of the first transistor means further being coupled to an output terminal of the pulse conversion apparatus, the first and the second transistor means each being fabricated upon a common substrate; and   means for inputting pulses of optical radiation to the control terminal of the first transistor means and for inputting pulses of optical radiation to the control terminal of the second transistor means for causing the first and the second transistor means to alternately toggle between a conducting state and a nonconducting state and for causing an electrical output signal appearing at the pulse conversion apparatus output terminal to toggle between a first logic state and a second logic state, the inputting means being integrally formed upon the common substrate with the first transistor means and the second transistor means for minimizing stray inductive and capacitive reactances for substantially eliminating temporal jitter of the electrical output signal, wherein the inputting means is comprised of a first photoconductor coupled to the control terminal of the first transistor means and a second photoconductor coupled to the control terminal of the second transistor means.   
     
     
       19. Pulse conversion apparatus for converting an optical pulse into an electrical pulse, comprising: first transistor means having an output terminal coupled to an associated load means, the first transistor means further having a control terminal;   second transistor means having an output terminal coupled to an associated load means, the second transistor means further having a control terminal, the first and the second transistor means being cross-coupled such that the control terminal of the first transistor means is coupled to the output terminal of the second transistor means and the control terminal of the second transistor means is coupled to the output terminal of the first transistor means, the output terminal of the first transistor means further being coupled to an output terminal of the pulse conversion apparatus, the first and the second transistor means each being fabricated upon a common substrate; and   means for inputting pulses of optical radiation to the control terminal f the first transistor means and for inputting pulses of optical radiation to the control terminal of the second transistor means for causing the first and the second transistor means to alternately toggle between a conducting state and a nonconducting state and for causing an electrical output signal appearing at the pulse conversion apparatus output terminal to toggle between a first logic state and a second logic state, the inputting means being integrally formed upon the common substrate with the first transistor means and the second transistor means for minimizing stray inductive and capacitive reactances for substantially eliminating temporal jitter of the electrical output signal, wherein the inputting means is comprised of at least a portion of the control terminal of each of the first and the second transistor means.   
     
     
       20. Pulse conversion apparatus for converting an optical pulse into an electrical pulse, comprising: first transistor means having an output terminal coupled to an associated load means, the first transistor means further having a control terminal;   second transistor means having an output terminal coupled to an associated load means, the second transistor means further having a control terminal, the first and the second transistor means being cross-coupled such that the control terminal of the first transistor means is coupled to the output terminal of the second transistor means and the control terminal of the second transistor means is coupled to the output terminal of the first transistor means, the output terminal of the first transistor means further being coupled to an output terminal of the pulse conversion apparatus, the first and the second transistor means each being fabricated upon a common substrate; and   means for inputting pulses of optical radiation to the control terminal of the first transistor means and for inputting pulses of optical radiation to the control terminal of the second transistor means for causing the first and the second transistor means to alternately toggle between a conducting state and a nonconducting state and for causing an electrical output signal appearing at the pulse conversion apparatus output terminal to toggle between a first logic state and a second logic state, the inputting means being integrally formed upon the common substrate with the first transistor means and the second transistor means for minimizing stray inductive and capacitive reactances for substantially eliminating temporal jitter of the electrical output signal, wherein the first and the second transistor means each include a bipolar transistor or a field effect transistor comprised of silicon, germanium, Group III-V material or combinations thereof.